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Re: Re:Number of hams worldwide?

>>> "Scott Avery WA6LIE" <wa6lie@msn.com> 10/30/04 9:09:47 PM >>>
>This is the first time I have heard of APRS-Voice-Alert.
>Makes sense if all NON-Digipeating stations ran a PL of 100.

Yes, that is what makes it so neat.    Only the mobiles do it
so they can detect each other in the blind.  The TM-D700 and 
TH-D7 APRS radios are dual band and so the users set
 * SIDE A to APRS on 144.39 (CTCSS-100)
 * SIDE B for all other 2m and 440 operations

But Its like 3 radios in one because side A not only drives the
the internal TNC and APRS front panel functions, but since it 
also has  CTCSS-100 then it is a guaranteed voice intercom 
alert channel that you can use to ALWAYS make voice contact
with an in-range APRS operator.
(The APRS V-A CTCSS is 123 in Europe where they have 50 Hz AC).

>It would let you know of local activity for sure!

But please note that this is only for 100% manned stations
(an operator is present).  No one likes to hear a "ping"
from an unattended station!!!!!  So anyone is welcome to
monitor 144.39  with CTCSS-100 for local mobiles, but
we absolutely dont want any HOME stations banging away
with ANY packets using the PL-100!  ARGH...

>Can APRS-Voice-Alert generate a PL somehow, or does 
>the user just run the  PL?

We absolutely do not want ANY mobiles running APRS 
packets with PL100 if they are NOT ALSO listening
with CTCSS-100 and with the VOLUME TURNED UP.
Remember, runniing APRS voice alert is like calling CQ.

Running PL-100 without ALWAYS listening is like
calling CQ on a TRANSMIT-ONLY station...  It makes
enemies real fast.

Only the Kenwood APRS radios typicall run Voice Alert
since they can run CTCSS-100 to totally mute the RX
speaker, yet the internal TNC still works perfectly for
supporting APRS.  But other mobile APRS stations can
do it if they connect their TNC internally to the discriminator
before the CTCSS mute circuit.  Most people dont
connect their external TNC that way, so that is why
typically only the Kenwood APRS mobiles do...

In Summary on 144.39:

* APRS Packet Mobiles  run CTCSS-100
    They will hear others similarly configured only.
    Running PL-100-only packets is VERBOTEN.
    (its like calling CQ with no receiver turned on).

* Voice monitoring CTCSS-100 for nearby mobiles is welcome

* Packet monitoring CTCSS-100 from a home APRS station
   is VERBOTEN!  Since it still TX's packets to the mobiles 
   and drives them nuts 24/7/365...

* ALWAYS QSY to 146.52 after voice contact is made.

>Where can I find out more info on this?
>Sounds pretty useful!

SEE:  http://www.ew.usna.edu/~bruninga/d700-faq.txt

de Wb4APR, Bob

----- Original Message ----- 
From: "Robert Bruninga" <bruninga@usna.edu>
To: <amsat-bb@AMSAT.Org>; <kd6ozh@AMSAT.Org>; <mlhammond@charter.net>;

Sent: Saturday, October 30, 2004 5:17 PM
Subject: Re: [amsat-bb] Re:Number of hams worldwide?

> >...that means 1 in 1000 people that could be hams are.
> I've always used the number of 1 in 500 in the USA
> This means when you are driving down the interstate,
> you pass another ham on average about once every
> 10 minutes.  BUT you can go all day and not get a QSO.
> and just listening to "52" never works unless you are
> calling CQ every 2 minutes because of  your relative
> 140 MPH crossing speed and the short range of direct
> comms.
> This is why APRS-Voice-Alert works so well.  Its an
> automatic Proximity Radar that will always alert you to
> another APRS-Voice Alert station in range.  Voice
> Alert is nothing more than setting CTCSS-100 on
> the North Americal APRS frequency of 144.39 that is
> in use everywhere.
> Of course that frequency is wall-to-wall packets from
> digipeaters, BUT NONE OF THEM ARE USING PL-100
> except the other mobile APRS-Voice-Alert stations, who
> just so happen to be also LISTENING for voice calls
> with CTCSS-100.  So no-one hears anything on the channel
> unless they are SIMPLEX range to another APRS-Voice-Alert
> station.  Then in a crossing situation they may hear  at most
> two or three once-a-minute  "braps" which alerts them to:
> 1) Another HAM in range LISTENING with CTCSS-100
> 2) You KNOW he has the radio on and is listening
> 3) You KNOW he is in range
> 4) You KNOW he is looking for a QSO
> 5) Bingo, instant QSO for the 3 or 4 minutes you are in range.
> Believe me, it sure beats 52.  And EVERY APRS operator
> is on 144.39 so there is no ambiguity.  So even if you are
> not a user of APRS, but are on a LONG drive and get
> tired of hearing nothing on "52".  Then simply QSY your
> voice rig to 144.39 and set CTCSS-100.   All the packets
> will be silenced and you wont hear anything.  But if you
> DO hear a packet, then it is from soneone else who
> IS LISTENING for a voice call!
> Of course, onnce you make contact, then QSY to "52"
> so that you dont have to fight all those packets!
> de Wb4APR, Bob 
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
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